Question 667692
Let distance from city A to city B be x miles

speed forward = 40 mph
return speed = 50 mph

total time 48 hours
less 15 hours at sister's place
48-15=33 hours

Time forward + time return = 33

time = d/r

{{{x/40 + x/50 = 33}}}

LCD = 200

multiply equation by 200

5x+4x=33*200

9x= 6600
x= 6600/9
733.33 miles is the distance from A to B